The Synology DS411slim is designed to work with 2.5” hard drives. The low power consumption characteristic of 2.5” hard drives will lower your electricity bill, as well as reduce your carbon footprint. In addition, 2.5” hard drives have reduced vibration, increased MTBF (mean time before failure), and shock tolerance. It not only extends hard drive’s lifespan, but also provides better reliability. The smart fan design keeps the DS411slim’s fan off under normal operations and spinning up at a very low speed only when needed, thus minimizing the noise level.